Desktop background picture keeps reverting to an old picture from months ago!

[luckEseven]

As stated in title, the desktop picture will randomly revert to a picture I had up there months ago, usually when I run the battery all the way down on my unibody MB, but also when I change display settings when i plug into an external monitor.

Do I just need just reset the PRAM or is there something else I'm missing.

BTW, I have searched and I know I only have a few posts...

 

[allan.nyholm]

How did you apply the desktop picture? I noticed that setting the image with iPhoto then under some circumstances I get sent back to the one I had originally with the Desktop and Screensaver prefpane.

I really have no idea other than the way the desktop picture is set might have something to do with it.